Free PMI Project Management Professional (PMP) Practice Question

The correct answer is that Activity X has 5 days of float. Float, also known as slack, is the amount of time an activity can be delayed without affecting the project's overall completion date. It is calculated as the difference between the Late Start (LS) and Early Start (ES) of an activity. In this case, LS (15) - ES (10) = 5 days of float.

This means that Activity X can start as early as Day 10 or as late as Day 15 without impacting the project's timeline. Understanding float is crucial for project managers as it helps in resource allocation and prioritizing tasks. Activities with zero float are on the critical path and require close monitoring, while those with float offer more flexibility in scheduling.